1.Field
Film formation.
2.Background
As process generations move forward, the sensitivity of circuit devices to higher fabrication temperatures increases. For example, the sensitivity of transistor components such as tips, wells, and implants to higher temperatures increases as these components become smaller and shallower. Higher temperatures cause implants, for example, to diffuse and adversely affect the implant and thus device performance.
Dielectric films are used in a number of instances in circuit fabrication. Silicon nitride is a common dielectric film that is typically formed by combining a silicon source precursor (e.g., a vapor) with a nitrogen source precursor (e.g., a vapor) in a deposition chamber. One current silicon source precursor is bis(tert-butyl amino) silane. When combined with a nitrogen source precursor such as ammonium (NH3), the reaction conditions to form a silicon nitride film generally require a temperature greater than 550° C. Such a chamber temperature can affect temperature sensitive devices as noted above and it is anticipated that the effect will be more pronounced as generations move forward.